PROJECT SUMMARY Labor migration is a major contributor to fueling the global AIDS epidemic and also the movement of HIV across country borders and populations. Migrants who inject drugs while in a host country are at especially high risk. Tajikistan, a small country in Central Asia, exports more than a million Tajiks annually, many of whom inject drugs, to work temporarily outside of their own country. Our earlier research on Tajik labor migrants in Moscow showed them to be at alarmingly high normative and behavioral risk for HIV due to risky drug use, needle sharing, alcohol consumption, and unsafe sex with casual and paid sex partners. To help curb transmission in this vulnerable population, we developed and pilot tested the Migrants' Approached Self- Learning Intervention in HIV/AIDS for Tajiks (MASLIHAT) prevention model. The model recruits and trains current and former Tajik migrants who inject drugs as peer educators in delivering the intervention to others in their social networks while simultaneously reducing their own risk. The MASLIHAT Intervention and our research efforts build synergistically on 3 theoretical models: social-cognitive-behavioral theory, social network theory and Yang's Theory of Migration. The model itself culturally adapts the successful SHIELD model, which is a CDC- designated evidence-based best practice intervention in the U.S., for use with Tajik labor migrants in Russia who inject drugs. This study will test the efficacy of the MASLIHAT intervention against a control condition designed to be equal to the intervention condition in the number of sessions, duration, and interest level. We will deliver MASLIHAT and control group interventions over 5 sessions with groups of 5 to 9 Tajik male migrants who inject drugs for a total of 10 groups for each intervention. The peer educators will share what they learned with others in their social networks, including the 2 network members who inject drugs whom they recruited for enrollment in the study. We will assess MASLIHAT and control participants and their Tajik male social network members at baseline and at 3, 6, 9 and 12 months post-intervention. We will conduct repeated measures linear and logistic regressions using mixed effect models with random person intercepts to test: (1) if greater changes in HIV risk behaviors, prevention self-efficacy, and behavioral norms occur among MASLIHAT participants (peer educators) compared to control participants, and (2) if greater changes in HIV risk behaviors, prevention self-efficacy, and behavioral norms occur among peer educator network members compared to control group network members. By transforming their own risk behavior, and encouraging others at risk to do so as well, migrant peer educators can initiate positive changes at the individual and social network levels in both their host country and also their home country when they return. The impact of the proposed study lies in the development of a much needed scientifically tested intervention that reduces HIV transmission among migrants who inject drugs within and across country borders.